Keio Dentetsu has released exterior and interior images of the new rolling stock it will use on reserved seat service to be introduced in the future. The order will be for 5 sets of 10 cars, to be built by J-TREC. Designated the 5000 series, they will begin operations in spring 2018. The seating will be of the rotatable type to match peak/off-peak conditions and reserved seat service.
http://www.keio.co.jp/news/update/news_release/news_release2015/nr160316_zasekishiteiressha.pdf
earlier thread:
http://www.jnsforum.com/community/topic/10046-keio-considering-for-fee-services/?hl=%2Bkeio+%2Bseating&do=findComment&comment=115321